From 44ef0ac41c17e2247f4e4f3b97e5f10688879598 Mon Sep 17 00:00:00 2001 From: Baitinq Date: Tue, 29 Nov 2022 01:23:34 +0100 Subject: [PATCH] shuf: Support the output of a limited number of lines This patch adds the "-n"/"--head-count" optional argument to specifiy the maximum number of shuffled lines to output. Idea from Andreas' FIXME roulette :^) --- Userland/Utilities/shuf.cpp | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/Userland/Utilities/shuf.cpp b/Userland/Utilities/shuf.cpp index c682ca1c92..e1e32780c3 100644 --- a/Userland/Utilities/shuf.cpp +++ b/Userland/Utilities/shuf.cpp @@ -20,9 +20,11 @@ ErrorOr serenity_main(Main::Arguments arguments) Core::ArgsParser args_parser; StringView path; + Optional head_count; bool is_zero_terminated = false; args_parser.add_positional_argument(path, "File", "file", Core::ArgsParser::Required::No); + args_parser.add_option(head_count, "Output at most \"count\" lines", "head-count", 'n', "count"); args_parser.add_option(is_zero_terminated, "Split input on \\0, not newline", "zero-terminated", 'z'); args_parser.parse(arguments); @@ -65,8 +67,8 @@ ErrorOr serenity_main(Main::Arguments arguments) } Array output_delimiter = { '\n' }; - for (auto const& line : lines) { - TRY(Core::System::write(STDOUT_FILENO, line)); + for (size_t i = 0; i < min(head_count.value_or(lines.size()), lines.size()); ++i) { + TRY(Core::System::write(STDOUT_FILENO, lines.at(i))); TRY(Core::System::write(STDOUT_FILENO, output_delimiter)); }